Can PBR be "faked" in Blender Internal or the Game Engine?
I found this video &amp; post really helpful for PBR for non-cycles renders: https://cgcookie.com/2015/05/20/pbr-in-blenders-viewport/

He uses 2 environment maps, one blurry and one sharp, and blends them in way that the sharp one is reflected on the edges and the blurry one is reflected in the front, the way fresnel reflections work. He uses a normal node to do the fresnel reflections in a clever way.

It works with environment maps, not specular (phong) shading, though personally I prefer the environment map look. Note that if you add a light the hilights you get won't match the reflections.

So it's a bit of a hack - 2 reflection maps needed, lights don't reflect right - but it works.